In the files_texteditor application, editor syntax highlighting was working in Nextcloud 13 for file types such as php.

After upgrade to version 15 of Nextcloud, the capability appears to be disabled. Tried on pure 15 install, and installation after upgrade from 13. With and without config/mimetypealiases.json and config//mimetypemapping.json files. Before and after issuing occ maintenance:mimetype:update-js.

Does there exist a config or modification to re-enable syntax checking inside the default Nextcloud editor?